diff --git a/client/GameEngine.cpp b/client/GameEngine.cpp
index 67c3f7bd8..30866a60a 100644
--- a/client/GameEngine.cpp
+++ b/client/GameEngine.cpp
@@ -23,21 +23,17 @@
 #include "media/CVideoHandler.h"
 #include "media/CEmptyVideoPlayer.h"
 
-#include "CPlayerInterface.h"
 #include "adventureMap/AdventureMapInterface.h"
 #include "render/Canvas.h"
 #include "render/Colors.h"
-#include "render/Graphics.h"
 #include "render/IFont.h"
 #include "render/EFont.h"
 #include "renderSDL/ScreenHandler.h"
 #include "renderSDL/RenderHandler.h"
-#include "CMT.h"
 #include "GameEngineUser.h"
 #include "battle/BattleInterface.h"
 
 #include "../lib/AsyncRunner.h"
-#include "../lib/CThreadHelper.h"
 #include "../lib/CConfigHandler.h"
 
 #include <SDL_render.h>
@@ -84,8 +80,8 @@ GameEngine::GameEngine()
 
 	soundPlayerInstance = std::make_unique<CSoundHandler>();
 	musicPlayerInstance = std::make_unique<CMusicHandler>();
-	sound().setVolume((ui32)settings["general"]["sound"].Float());
-	music().setVolume((ui32)settings["general"]["music"].Float());
+	sound().setVolume(settings["general"]["sound"].Integer());
+	music().setVolume(settings["general"]["music"].Integer());
 	cursorHandlerInstance = std::make_unique<CursorHandler>();
 
 	asyncTasks = std::make_unique<AsyncRunner>();
@@ -244,7 +240,7 @@ std::shared_ptr<IStatusBar> GameEngine::statusbar()
 	return locked;
 }
 
-void GameEngine::setStatusbar(std::shared_ptr<IStatusBar> newStatusBar)
+void GameEngine::setStatusbar(const std::shared_ptr<IStatusBar> & newStatusBar)
 {
 	currentStatusBar = newStatusBar;
 }
diff --git a/client/GameEngine.h b/client/GameEngine.h
index 69d99f681..80dee43e2 100644
--- a/client/GameEngine.h
+++ b/client/GameEngine.h
@@ -58,6 +58,8 @@ private:
 	IGameEngineUser *engineUser = nullptr;
 
 	void updateFrame();
+	void handleEvents(); //takes events from queue and calls interested objects
+	void drawFPSCounter(); // draws the FPS to the upper left corner of the screen
 
 public:
 	std::mutex interfaceMutex;
@@ -102,7 +104,9 @@ public:
 	std::shared_ptr<IStatusBar> statusbar();
 
 	/// Set currently active status bar
-	void setStatusbar(std::shared_ptr<IStatusBar>);
+	void setStatusbar(const std::shared_ptr<IStatusBar> &);
+
+	/// Sets engine user that is used as target of callback for events received by engine
 	void setEngineUser(IGameEngineUser * user);
 
 	bool captureChildren; //all newly created objects will get their parents from stack and will be added to parents children list
@@ -111,15 +115,17 @@ public:
 	GameEngine();
 	~GameEngine();
 
+	/// Performs main game loop till game shutdown
+	/// This method never returns, to abort main loop throw GameShutdownException
 	[[noreturn]] void mainLoop();
 
 	/// called whenever SDL_WINDOWEVENT_RESTORED is reported or the user selects a different resolution, requiring to center/resize all windows
 	void onScreenResize(bool resolutionChanged);
 
-	void handleEvents(); //takes events from queue and calls interested objects
+	/// Simulate mouse movement to force refresh UI state that updates on mouse move
 	void fakeMouseMove();
-	void drawFPSCounter(); // draws the FPS to the upper left corner of the screen
 
+	/// Returns true for calls made from main (GUI) thread, false othervice
 	bool amIGuiThread();
 
 	/// Calls provided functor in main thread on next execution frame
diff --git a/clientapp/EntryPoint.cpp b/clientapp/EntryPoint.cpp
index 235a7e4b3..6ab52e40f 100644
--- a/clientapp/EntryPoint.cpp
+++ b/clientapp/EntryPoint.cpp
@@ -235,14 +235,14 @@ int main(int argc, char * argv[])
 	}
 
 	Settings session = settings.write["session"];
-	auto setSettingBool = [&](std::string key, std::string arg) {
+	auto setSettingBool = [&](const std::string & key, const std::string & arg) {
 		Settings s = settings.write(vstd::split(key, "/"));
 		if(vm.count(arg))
 			s->Bool() = true;
 		else if(s->isNull())
 			s->Bool() = false;
 	};
-	auto setSettingInteger = [&](std::string key, std::string arg, si64 defaultValue) {
+	auto setSettingInteger = [&](const std::string & key, const std::string & arg, si64 defaultValue) {
 		Settings s = settings.write(vstd::split(key, "/"));
 		if(vm.count(arg))
 			s->Integer() = vm[arg].as<si64>();
@@ -280,7 +280,7 @@ int main(int argc, char * argv[])
 	logGlobal->debug("settings = %s", settings.toJsonNode().toString());
 
 	// Some basic data validation to produce better error messages in cases of incorrect install
-	auto testFile = [](std::string filename, std::string message)
+	auto testFile = [](const std::string & filename, const std::string & message)
 	{
 		if (!CResourceHandler::get()->existsResource(ResourcePath(filename)))
 			handleFatalError(message, false);
diff --git a/lib/AsyncRunner.h b/lib/AsyncRunner.h
index 94ce6e44b..5d9496bd4 100644
--- a/lib/AsyncRunner.h
+++ b/lib/AsyncRunner.h
@@ -9,23 +9,27 @@
  */
 #pragma once
 
-#include <tbb/task_group.h>
 #include <tbb/task_arena.h>
+#include <tbb/task_group.h>
 
 VCMI_LIB_NAMESPACE_BEGIN
 
+/// Helper class for running asynchronous tasks using TBB thread pool
 class AsyncRunner : boost::noncopyable
 {
 	tbb::task_arena arena;
 	tbb::task_group taskGroup;
 
 public:
-	template <typename Functor>
+	/// Runs the provided functor asynchronously on a thread from the TBB worker pool.
+	template<typename Functor>
 	void run(Functor && f)
 	{
 		arena.enqueue(taskGroup.defer(std::forward<Functor>(f)));
 	}
 
+	/// Waits for all previously enqueued task.
+	/// Re-entrable - waiting for tasks does not prevent submitting new tasks
 	void wait()
 	{
 		taskGroup.wait();